Sodium Bicarbonate in Intra-dialytic Hypertension in Chronic Hemodialysis Patients

Inclusion Criteria: * Chronic hemodialysis patient \> 3 months * 3 dialysis per week, KTV\>1.2 * capable of informed concent. * rise in blood pressure during hemodialysis \> 10 mm Hg, for at least 50% of dialysis sessions in the month prior to inclusion. * Normal volume status, by clinical physician assessment + bioimpedance Exclusion Criteria: * age under 18, * pregnancy * unable to sign informed concent * planned for kidney transplant in the following 3 month. * congestive heart failure (NYHA 3-4) * hospitalization for acute MI or CHF in the past 3 months. * low compliece to medical therapy * regular pre-dialysis tests with bicarbonate \> 24 in the past 3 months